Comparative efficacies of commonly used disinfectants and antifungal pharmaceutical spray preparations against dermatophytic fungi

Arthroconidia from five fun al strains belonging to three Trichophyton spec ies, Trichophyton mentagrophytes, T. raubitschekii and T. tonsurans, were t ested against commercial chemical disinfectants and pharmaceutical antifung al agents. The chemical disinfectants included chlorine, phenol, sodium dod ecyl sulphate and several quaternary ammonium salts, while the two pharmace utical preparations contained bifonazole and terbinafine as active agents. Arthroconidia were exposed to the antifungal agent either in a suspension s olution for a given period of time and assayed for kill rate, or on a spray ed agar plate and monitored for surviving colonies over a period of 14 days . Chlorine (1%) and terbinafine (0.01%) were found to be high level disinfe ctants bringing about a rapid inactivation of conidia in all five strains. Phenol was equally effective against T. raubitschekii and T. tonsurans; how ever, T. mentagrophytes cells were able to survive for up to 1 h in 5% phen ol. Quaternary ammonium compounds were less rapid in their action against d ermatophytes and were needed at a level of about 0.5% to be completely fung icidal. Three commercial spray formulations with a range of 0.1 to 0.3% qua ternary ammonium salts were fungistatic against T mentagrophytes strains. B ifonazole (1%) was also fungistatic in its action against T. mentagrophytes . Sodium dodecyl sulphate (0.5%) was largely ineffective against Trichophyt on arthroconidia.